Thermostatic switch



Jan. 9, 1934- T. A. SCHAEFER THERMOSTATIC SWITCH Filed March 2, 1931 W Cu. K a Y R Q E m /MZM N Y m M7 N Patented Jan. 9, 1934 THERMOSTATIC SWITCH Timothy A. Schaefer, Winegar, Wis.

Application March 2, 1931. Serial No. 519,552

2 Claims.

This invention relates to improvements in thermostatic circuit closures.

One of the objects of the present invention is the provision of a device of the above character which can be used for a great many purposes, such as closing the circuit to fire alarms, closing the circuit to electric refrigerators, and for a great many household uses, as well as for use in large tracts of timber where the device could be set so as to be actuated by any fire occurring in the timber.

Another object of the present invention is the provision of a simple and inexpensive thermostatic closure which can be placed on the market at a very low cost and which can be used for various purposes where a circuit closure is desired, and will operate equally as efiicient as a more expensive or complicated device of this character.

A further object of the present invention is the provision of a thermostatic circuit closure, which can be readily adjusted so that the same will close the circuit in various degrees of temperatures, whether it be either hot or cold temperatures, and can be quickly and easily set for operation at any predetermined temperature.

With the above and other objects in view, the invention consists the novel features of construction, the combination and arrangement of parts hereinafter more fully set forth, pointed out in the claims and shown in the accompanying drawing wherein:

Figure 1 is a top plan view with a portion of the cover removed;

Figure 2 is a sectional view on the line 2-2 of Figure 1;

Figure 3 is a sectional view on the line 3 of Figure 1;

Figure 4 is a detailed section on the line 4-4 of Figure 1;

Figure 5 is a detailed section of the adjustable mounting for the thermostatic element illustrated in Figure 4;

Figure 6 is a detailed elevation of a modified form of mounting; and,

Figure '7 is a detailed vertical section of the showing illustrated in Figure 6.

It is the specific purpose of this invention to provide a simple type of thermostatic circuit closure with a minimum number of elements so that the device can be placed on the market at a very low cost for various uses. The device itself in eludes a base member 1 having laterally projecting apertured end flanges 2, whereby the base can be secured to any suitable support by passing screw members or other fastening elements through the aperture 3.

Attached to the base and insulated therefrom is a contact arm 4 having an offset end 5 which carries an adjustable binding post 6.

The inner end of the arm 4 is attached to the base 1 by means of a contact pin 7 which passes through the base and has a suitable washer 8 on the lower end thereof, spaced from the base by an insulating plate 9. It will be noted that the lower end of the pin '7 is overturned or headed at 10 to retain the washer 8 in position. An insulating strip 11 is mounted upon the base 1, positioned between the arm 4, and the base. The pin 7 is also insulated from the base 1 by means of an insulated sleeve surrounding the pin and positioned within an opening in the base. The upper end of the pin is provided with an enlarged head. 12 which forms a suitable contact for the thermostatic element Struck out from the base member is a portion of metal which is bent upwardly at right angles to the base to form a supporting standard 14. Pivotally mounted upon this standard 14 is a movable arm 15, and extending through the upper end of arm 15 is a stub shaft 16 having the coiled thermostatic element 13 mounted on one end thereof and positioned at one side of the arm 15. A washer 17 is mounted on the stub shaft at the other side of the arm and a cross pin 18 retains the washer 17 in position. Mounted upon the shaft 16 and disposed between the arm 15 and the washer 1'? is a coil spring 19 which retains the shaf 15 in various rotative adjustments.

The thermostatic element 13 is secured at one end to the shaft 16, while the other or outer end extends laterally of the shaft 16 and is positioned above the head 12 of pin 7, as shown in Figure 2 to form a contact 20.

The arm 15 carries a pivot bolt 21 which passes through the standard 14 and has a nut 22 for clamping the washer 23 against one face of the standard 14. The standard 14 is rounded at its upper end and extending around the rounded portion are a plurality of graduations as indi cated in Figure 4, whereby the contact arm 20 can be set to various positions so that when a predetermined temperature is reached in the room in which the circuit closure is located, the contact arm 20 will engage contact head 12 of pin '7 for closing a circuit through the binding post 6. A conductor 24 is connected to the binding post 6 and a second binding post 25 is carried by the base and has a conductor 24 attached thereto.

The upper portion of the base, as well as the various elements supported thereby are preferably enclosed within a cover or housing generally indicated at 26. The ends of the housing adjacent the lower ends thereof are provided with inwardly projecting lugs 2'7 adapted to engage in suitable indentations 28 for retaining the cover in position. This housing or cover 26 can be provided with a plurality of apertures 29 and when this device is used in a forest, or similar place, where insects would pass through the apertures 29, a fine screen can be placed inside of the housing in order to prevent the insects from entering the same through the apertures 29. By forming the apertures 29 in the housing 26, it will reduce the weight of the entire device, and also provide for a thorough circulation of the atmosphere at the correct temperature around the thermostatic element 13.

In Figures 6 and '7, I have illustrated a slight modification of ans whereby to provide a comparatively fine a ustment for the thermostatic element under various-degrees of temperature. In this form of th .ention, the base 1 is provided with an n; idin standard portion 14 which carries the ar' 15 for supporting the thermostatic element. The upper portion of this standard 14 is provided with a plurality of apertures 30 adapted to receive a projecting lug 31 carried by the graduated disc 32, and a pivot bolt 21 supports the l5 and the rotatable disc 32.

In the use of the main form of the invention, it will be noted t the graduated portion at the upper end of the s 'idard i is somewhat limited and when this per user standard is used in connection with the other parts of the device, the circuit closure will be preferably constructed for use for speci ed c-urposes. Attention is also directed to the ct that the thermostatic element which is moun ed on the shaft 16 must be of a type actuated by when it is desired to close a circuit under certain heated conditions. In setting the device, the shaft 16 rotated until the contact arm 20 engages the head 12 and iron this position, the graduations on the standard 14 will cooperate with the indicated point 33 on the arm 15 and will i1 dicat-e th e ree or" temperature desired for closing the circuit. A range of temperature can then be 0?" ained by adjusting the arm 15 to the left in Figure 4 to any desire-:1 point.

However, as soon as the temperature in the room reaches the first indicated degree, the arm 20 will be urged into contact with the head 12 for closing the circuit through the conductors 24 and 24, thus signifying the fact that the temperature where the device is located has reached a predetermined degree.

In the modified form shown in Figures 6 and '7, the arm 15 is moved laterally of the standard 14 until the contact arm 20 engages the head 12. If the device is to be used where the thermostatic element will be actuated by rays of heat, the disc 32 is set so that predetermined graduations thereof align with the indicated point 33 of the arm 15, and through the medium of the lug 31, fitting in one of the indentations 30, the disc 32 will be retained in position. The arm 15 can then be moved laterally to space the arm 20 from the head 12, and the arm 20 will not engage the head 12 until a predetermined degree of heat has been reached in the place in which the device is located.

However, as soon as the temperature reaches this degree, the thermostatic element 13 is actuated to move the arm 20 into contact with the head 12 and close the circuit.

It will be apparent from the foregoing that this device can be used in a great many places and set for a great many ranges of temperature, so that the same can be universally used for various purposes.

The device is extremely simple in construction and due to this fact, it can be placed on the market at a low price for use in small house- 100 holds, and other similar places.

I claim:

1. A thermostatic switch comprising, a base, a normally fixed contact carried by said base, a swingably adjustable arm, a pivot swingably connecting one portion of said arm to said base, means coacting directly with said pivot and with the adjacent arm portion for holding said arm in an adjusted position relative to said base, a spirally wound thermostatic element having at its outer end a contact portion which is movable toward and away from said fixed contact, a sec ond pivot connecting the inner end of said element to a swingable portion of said arm remote from said first mentioned pivot, and means coacting directly with said second pivot and with the adjacent arm portion for holding said element in an adjusted position relative to said arm.

2. A thermostatic switch comprising, a sheetmetal base having an integral ear, a normally .33: fixed contact carried by said base, a swingably adjustable arm, a pivot swingably connecting an end of said arm to said ear, means ooacting di rectly with said ear and with said arm end for frictionally holding said arm in various positions of adjustment relative to said car, a spirally wound thermostatic element having at its outer end a contact portion which is movable toward and away from said fixed contact, a second pivot connecting the inner end of said element to a swinging portion of said arm remote from said pivoted arm end, and means coacting directly with said second pivot and with the adjacent arm portion for frictionally holding said element in various positions of adjustment relative to said N- arm.

TIMOTHY A. SCHAEFER. 

